#snake genetics

To summarize/explain:

OP relays that mom snake was purchased as a tessera. 16 eggs hatched, no tesseras but one stripe and 2 motleys are present. Meaning 13 babies were normal patterned (important).

A picture of mom was provided, showing that she is visually a motley. Because she produced a striped baby, that means genetically she is a motley-stripe (motley and stripe share the same spot in the genome. They are allelic to each other.) In a genetic motley-stripe the motley gene completely masks the stripe gene and the animal will look like a motley. The stripe gene has no effect on the motley pattern at all.

Because normal babies were produced, we know that the dad is not a motley or a stripe because otherwise every baby in the clutch would be a visual motley or stripe. Visual motley to visual motley, visual motley to stripe, and stripe to stripe cannot, genetically, produce offspring with a normal pattern (barring extremely rare genetic fuckery. We're keeping things neat here)

Because a stripe baby was produced, we know the dad must be carrying *one* copy of the stripe gene. As he *only* has a stripe gene to offer to his offspring, the motley patterned babies are actually genetic motley-stripes. And all the normal patterned babies in this current clutch are either het motley OR stripe but NOT both, thanks to mom.

I informed OP of this in a similar fashion and said that if paired to a stripe the dad will only be able to produce normal patterned and striped babies.

Then comes in

Mr. Motley

"If the dad is motley/stripe paired with a stripe he would still produce motleys and stripes..Motley is dominant to stripe in the gene pool..Matter fact if he bred the stripe and carried no stripe he would produce all motley babies het stripe..(motley/stripes) ..The motley babies do seem to come out with a lot of striping.."

to which I responded:

"The dad isn't a motley. Only 2 motleys and the one stripe were produced.

to quote OP: "only 3 aren’t the wild-type pattern haha"..."

Anyway. Hope you have a lovely day :)

Hey friend!

PH means "possibly heterozygous," and the percentage is about how possible the heterozygous-ness is.

This comes up when you have one or both parent snakes who are known to be heterozygous for a recessive trait, but it's not certain whether or not their offspring are het since it's not visible. This isn't an arbitrary number nor a guarantee of genetics, it's just a statistical probability that the snake is carrying that gene.

For example, let's say you are breeding two wild-type corn snakes and one is het for the recessive Amelanistic gene. The babies will have a 50/50 chance of inheriting the Amel gene, but they would also be het since they can only get one copy of the trait from the one parent who carries it. Since you can't see a heterozygous recessive trait, all of the babies would be listed as 50% possibly heterozygous for Amelanism, or 50% PH Amel.

If both parents are het for Amel and neither are homozygous, statistically about 1/4 of the babies would be homozygous visual Amel, 2/4 would be heterozygous Amel wild-types, and 1/4 would be of the babies would be wild-types with no heterozygous traits at all. Percentage-wise, the wild-type babies would be 66.667% PH Amel.

Of course, nature doesn't exactly adhere to statistics, so any time you see "PH" consider it a possible bonus or advisement, but not a guarantee of genetics.

Hey friend! 

First off, thank you so much for your kind words. :) I’m very happy about this hatching season and very excited to share all of these new faces with everyone!

Second, your very excellent question has a very simple answer with a somewhat less simple elaboration.

Answer: They’re different genes that coincidentally look similar. Tessera is dominant, Terrazzo and Stripe are recessive. Visually, Tessera usually results in very bold patterning that goes from head to tail, while Terrazzo tends to fade out towards the tail end of the snake, and Stripe is often somewhere in the middle between bold and faded.

More Answer: (under a cut because verbosity reasons)